close

Вход

Забыли?

вход по аккаунту

?

JP2008228248

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2008228248
An object of the present invention is to provide a speaker provided with an acoustic pipe on the
sound emitting side, which has high mechanical strength of a drive unit and eliminates the
possibility of burnout or destruction due to heat generation. A speaker (10) is a speaker
including an acoustic tube (15) on the sound output side, and includes a housing (11), a giant
magnetostrictive member (12), and a magnetic field generation unit (14). The housing comprises
a phase equalizer 16 disposed within the acoustic tube. The giant magnetostrictive member is
disposed in the housing, displaced in response to the change of the magnetic field, and vibrates
air directly by the displaced end. The magnetic field generation unit is disposed at intervals
around the giant magnetostrictive member, and generates a magnetic field in response to the
supply of the drive current based on the audio signal. When the drive current based on the audio
signal is supplied to the magnetic field generator, the magnetic field generator generates a
magnetic field. The generated magnetic field is applied to the giant magnetostrictive member,
and the giant magnetostrictive member stretches and displaces based on the giant
magnetostrictive member, thereby vibrating as a drive unit. [Selected figure] Figure 1
スピーカ
[0001]
The present invention relates to a speaker including an acoustic tube on the sound output side,
and more particularly, to a speaker that uses a giant magnetostrictive element and displaces the
giant magnetostrictive element based on an audio signal to reproduce sound.
[0002]
05-05-2019
1
So-called horn type speakers and air flow type speakers are known as speakers provided with an
acoustic tube on the sound emission side.
For example, a horn-type speaker is an acoustic transformer that improves acoustic conversion
(reproduction) efficiency, and is often used mainly for the generation of sound waves in the
middle to high temperature range. Further, since this speaker is an acoustic transformer, the
acoustic impedance of the drive unit is extremely high, and a lightweight material such as
duralmin or the like and a high strength material is used for the diaphragm and the peripheral
support of the diaphragm.
[0003]
An example of such a horn speaker is shown in FIG. In FIG. 4, the horn-type speaker 100 includes
a driver unit including a yoke 101, a diaphragm 102, a permanent magnet 103, a voice coil 104,
and a horn throat 107 having a phase equalizer 106, and a horn 105. ing. The yoke 101 includes
a center pole 108 at the center. An annular permanent magnet 103 is disposed to surround the
proximal end outer periphery of the center pole 108. The permanent magnet 103, the yoke 101,
and the center pole 108 constitute a magnetic circuit. The horn-type speaker 100 further
includes a voice coil 104 surrounded by a gap on the outer periphery of the center pole 108 in
the magnetic circuit, and the diaphragm 102 is attached to the tip of the voice coil 104. A horn
105 is disposed on the sound output side of the diaphragm 102 so as to surround the phase
equalizer 106 together with the phase equalizer 106. The horn 105 is an acoustic tube whose
cross section gradually changes toward the sound emission side (see Non-Patent Document 1).
[0004]
However, such a horn-type speaker 100 requires many steps for assembly, such as bonding the
voice coil 104 to the diaphragm 102 and attaching the edge portion of the voice coil 104 to the
base. In addition, when an audio signal in a low-pitch range is input, the diaphragm 102 does not
vibrate, so that the voice coil 104 may generate heat and burn. In addition, the voice coil 104 is
in the magnetic pole and is insulated because the air layer is on the side of the diaphragm 102,
and it is very difficult to dissipate heat to prevent burnout. Therefore, in order to prevent the
voice coil 104 from being burnt out, only the high / mid range audio signal is supplied to the
horn type speaker 110 through the low cut filter.
05-05-2019
2
[0005]
On the other hand, an air flow type speaker modulates the flow of air having a constant flow
velocity with an air flow valve operated by an electric signal to generate sound. An example of
such an air flow type speaker is shown in FIG. In FIG. 5, the air flow type speaker 110 includes a
housing 111 having an air inlet 117 through which compressed air flows and an air outlet 111a
consisting of a large number of small vents. In the housing 111, an air flow valve 116 for
adjusting the amount of air passing through the air vent of the air outlet 111a, an armature 118
connected to the air flow valve 116 to drive the air flow valve 116, and according to an input of
an audio signal. The permanent magnet 113 and the coil 114 are provided to vibrate the
armature 118. In addition, the air flow valve 116 includes an adjustment spring 119. The air flow
type speaker 110 is provided with a horn 115 on the sound output side that efficiently radiates a
sound wave propagated by the air passing through the air outlet 111a (see, for example, Patent
Document 1, Patent Document 2, or Non-Patent Document 2). ).
[0006]
However, in the air flow type speaker 110 described above, since the air flow valve 116 is a
portion that changes the flow rate of compressed air, when the mechanical strength of this
portion is low, the air flow valve may be broken. Therefore, the air flow valve 116 needs to have
a sufficiently high mechanical strength against the pressure of the compressed air and the
reaction by the flowing air. Further, since the mechanical impedance of the air flow valve 116 is
extremely high, the magnetic type air flow valve 116 as shown in FIG. 5 is used, but the air flow
valve 116 is inferior in frequency response.
[0007]
In addition, as an air flow type speaker, although not shown, a structure of an electromagnetic
induction type is also known in which a signal current is supplied to a field coil and a ring-shaped
one-turn coil is used as a movable portion. However, such an air flow speaker is very complicated
in structure and requires many steps for assembly.
[0008]
05-05-2019
3
In addition, several speakers have been proposed that use supermagnetostrictive elements and
displace the supermagnetostrictive elements based on audio signals to reproduce sound (see, for
example, Patent Document 3 or Patent Document 4). However, a speaker using such a giant
magnetostrictive element has an acoustic tube on the sound output side, and does not improve
the acoustic conversion (reproduction) efficiency. Japanese Utility Model Application Publication
No. 50-150325 Japanese Patent Application Laid-Open No. 62-62700 Japanese Patent
Application Laid-Open No. 2005-167722 Japanese Patent Application Laid-Open No. 2005277471 Audio Handbook, published by Ohm Co., Ltd., p. 280-p. Radio and Experiment,
December 2001, p55-p59 "100 Years of Speaker Technology"
[0009]
The present invention has been made in view of the above circumstances, and it is an object of
the present invention to provide a speaker having an acoustic tube on the sound output side,
which has high mechanical strength of the drive unit and eliminates the possibility of burnout or
destruction due to heat generation With the goal.
[0010]
A speaker according to the present invention is a speaker including an acoustic tube on the
sound output side, and includes a housing, a super magnetostrictive member disposed in the
housing and displaced according to a fluctuation of a magnetic field, and a periphery of the super
magnetostrictive member And at least a magnetic field generation unit for generating a magnetic
field in response to the supply of the drive current based on the audio signal.
[0011]
According to the speaker of the present invention, when the drive current based on the audio
signal is supplied to the magnetic field generator, the magnetic field generator generates a
magnetic field corresponding to the audio signal.
The generated magnetic field is applied to the giant magnetostrictive member, and the giant
magnetostrictive member stretches and displaces based on the giant magnetostrictive member,
thereby vibrating as a drive unit.
Thereby, a sound wave can be generated and emitted by the displacement end of the giant
05-05-2019
4
magnetostrictive member. Further, the sound wave emitted by the displacement end portion is
incident on the acoustic tube, and is further guided to the opening of the acoustic tube, so that
the efficiency of the acoustic conversion (reproduction) can be improved to be a speaker for
reproducing sound. Therefore, the mechanical strength of the drive unit is high, and a speaker
provided with an acoustic tube on the sound emitting side is provided, which eliminates the
possibility of burnout or destruction due to heat generation as seen in a horn-type speaker
provided with a conventional voice coil. You can do it.
[0012]
Hereinafter, an embodiment of a speaker according to the present invention will be described in
detail based on the drawings. The speaker according to the present invention is a horn type
speaker (hereinafter simply referred to as "first speaker"). And air flow type speakers (hereinafter
referred to simply as "second speakers"). Can be divided into First Embodiment First, a first
speaker will be described. FIG. 1 is a longitudinal side view showing an example of a first speaker
as a first embodiment of a speaker according to the present invention. As shown in FIG. 1, the
first speaker 10 is a speaker including an acoustic tube 15 on the sound output side, and
includes at least a housing 11, a giant magnetostrictive member 12, and a magnetic field
generation unit 14.
[0013]
The housing 11 is a case for housing the giant magnetostrictive member 12 and the magnetic
field generation unit 14 or the like, and can be, for example, a bottomed cylindrical hollow body
having an opening on the sound output side.
[0014]
The giant magnetostrictive member 12 is disposed in the housing 11 and is made of a giant
magnetostrictive element that has the property of being displaced (stretched) according to the
fluctuation of the magnetic field.
The super magnetostrictive member 12 has, for example, a cylindrical shape, and the base end
portion is fixed to the bottom surface of the housing 11. The super magnetostrictive member 12
directly vibrates air by its displacement end 12a.
05-05-2019
5
[0015]
The giant magnetostrictive element is an element made of, for example, a single crystal alloy or
powder metallurgy containing terbium, dysprosium, iron and the like as main components. This
giant magnetostrictive element causes a change in the amount of magnetization extending due to
the Joule effect when the magnetic field is applied from the outside, or causes a change in
dimension extending along the direction of the external magnetic field due to the Joule effect.
And have the property of being compressed and deformed. In addition, the giant
magnetostrictive element has extremely high mechanical strength such as compressive strength
of 600 × 10 <6> (Pa) and tensile strength of 20 × 10 <6> (Pa). In addition, Young's modulus is
also extremely high at 2.0 × 10 <6> (N / m <2>). As described above, since the giant
magnetostrictive member is formed of an element having high mechanical strength, it does not
burn out due to heat generation. Moreover, since the Young's modulus is high, it is possible to
secure the response to high frequency.
[0016]
The magnetic field generation unit 14 is a magnetic field generation coil which is disposed
around the giant magnetostrictive member 12 and generates a magnetic field oriented in the
direction of displacement of the giant magnetostrictive member 12 according to the supply of a
drive current based on an audio signal. . The magnetic field generation unit 14 may be disposed
at an interval to the periphery of the giant magnetostrictive member 12 or may be disposed in
contact with the giant magnetostrictive member 12.
[0017]
The acoustic tube 15 is a so-called horn which is provided continuously with the sound output
side of the housing 11 and gradually expands in diameter forward (upward in FIG. 1). A sound
path is formed by the arc-shaped inner wall surface of the acoustic tube 15.
[0018]
In addition, the housing 11 includes a phase equalizer 16 disposed in the acoustic tube 15. The
05-05-2019
6
phase equalizer 16 is a so-called equalizer, and is spaced apart from the acoustic pipe 15 in the
radial direction by, for example, a plurality of radially extending coupling members (not shown).
The acoustic pipe 15 and the phase equalizer 16 are fixed by any means such as bonding or
screw fixing, for example. Further, between the acoustic tube 15 and the phase equalizer 16 is
formed a throat portion 17 which is a passage of sound emitted by the giant magnetostrictive
member 12.
[0019]
In the first speaker 10 according to the present embodiment configured as described above,
when the drive current based on the audio signal is supplied to the magnetic field generation unit
(magnetic field generation coil) 14, the magnetic field generation unit 14 functions as an axis of
the giant magnetostrictive member 12. Generate a magnetic field oriented along the direction. In
addition, the giant magnetostrictive member 12 vibrates (extends and contracts) in the axial
direction (the direction of the arrow in the drawing) by the application of the magnetic field, and
the dimension (length) is displaced according to the audio signal. As a result, this displacement is
directly transmitted to the air and vibrates, and the vibration outputs a sound.
[0020]
As described above, the first speaker 10 according to the present embodiment is easy to
assemble and operates the displacement end 12a of the giant magnetostrictive member 12 like a
conventional diaphragm, so that the displacement end is not used. In the portion 12a, air can be
directly vibrated as a vibration medium (vibration amplitude of air can be changed) to generate
and emit a sound wave. Moreover, the sound wave radiated from the displacement end 12 a of
the giant magnetostrictive member 12 propagates between the inner circumferential surface of
the acoustic tube 15 and the outer circumferential surface of the phase equalizer 16, and the
high frequency range is generated by the phase equalizer 16. Phase correction of the sound wave
is made. Therefore, in the present embodiment, the driven portion is a super magnetostrictive
member with high mechanical strength, and the drive portion can be a speaker that is not burnt
out due to heat generation. In addition, without using a filter, burnout due to heat generation of
the voice coil can be prevented, and unnecessary sound waves can be prevented from being
emitted.
[0021]
05-05-2019
7
In the present invention, as shown in FIG. 2, the speaker 20 may further include a radiator 18
near the magnetic field generation unit 14. That is, in the present invention, since the magnetic
field generation unit 14 for flowing the signal current is fixed without moving, the radiator 18 for
dissipating the heat generated by the coil can be easily installed. By providing the radiator 18 in
this manner, the heat generation of the magnetic field generation unit 14 due to the drive current
is suppressed, and the magnetic field generation unit 14 is not easily disconnected as in the voice
coil described above, and burnout occurs. The risk can be reduced.
[0022]
Further, in the present invention, although not shown, the surface of the super magnetostrictive
member 12 may be subjected to anti-corrosion treatment. That is, in the present invention,
corrosion resistance due to rain, wind, etc. can be prevented and the weather resistance can be
made excellent by subjecting the surface of the super magnetostrictive member to be the drive
portion to the corrosion resistance treatment. This anti-corrosion treatment is performed, for
example, by applying a resin containing a corrosion inhibitor. Further, the anti-corrosion
treatment is not limited to the giant magnetostrictive member 12 but may be applied to the
acoustic tube 15 or the like. By performing the anti-corrosion treatment in this way to make it
excellent in weather resistance, an outdoor loudspeaker can be obtained.
[0023]
Second Embodiment Next, a second speaker will be described. As a second embodiment of the
speaker according to the present invention, FIG. 3 is an air flow type speaker (hereinafter simply
referred to as "second speaker"). ) Is a longitudinal side view showing an example of. As shown in
FIG. 3, the second speaker 30 is a speaker including an acoustic tube 35 on the sound output
side, and includes at least a housing 31, a giant magnetostrictive member 32, and a magnetic
field generation unit 34.
[0024]
The housing 31 is a case for housing the giant magnetostrictive member 32, the magnetic field
generating unit 34 and the like, and an air flow comprising an air inlet 37 for taking in
compressed air and a large number of small vents for blowing out the compressed air from the
sound emission side And an outlet 38, and may be a hollow body.
05-05-2019
8
[0025]
The giant magnetostrictive member 32 is disposed in the housing 31 and is made of a giant
magnetostrictive element that has the property of being displaced (stretched) according to the
variation of the magnetic field.
The super magnetostrictive member 32 has, for example, a cylindrical shape, and the base end
portion is fixed to the bottom surface of the housing 31. The super magnetostrictive member 32
is provided at its displaced end with an air flow valve 36 for adjusting the flow rate of
compressed air blown out from the air outlet 38 in correspondence with each air outlet 38.
[0026]
The air flow valve 36 is configured such that the vibration surface 36 a is formed in a concavoconvex shape, and the end face of the convex portion faces the air outlet 38, and the vibration
surface 36 a faces the air outlets 38. It is placed in position. The air flow valve 36 regulates the
amount of air passing through the air outlet 38. The amount of air is adjusted according to the
audio signal, and a sound wave corresponding to the amount of air is generated according to the
principle of whistle. Further, since the air flow valve 36 vibrates in conjunction with the
operation of the displacement end of the giant magnetostrictive member 32, the air flow valve 36
moves in parallel with the sound output side of the casing 31. As a result, the size of the air flow
path toward each air outlet 38 is uniformly controlled without variation, and the possibility of
waveform distortion occurring in the emitted sound can be eliminated.
[0027]
The giant magnetostrictive element is an element made of, for example, a single crystal alloy or
powder metallurgy containing terbium, dysprosium, iron and the like as main components. This
giant magnetostrictive element causes a change in the amount of magnetization extending due to
the Joule effect when the magnetic field is applied from the outside, or causes a change in
dimension extending along the direction of the external magnetic field due to the Joule effect.
And have the property of being compressed and deformed. In addition, the giant
magnetostrictive element has extremely high mechanical strength such as compressive strength
of 600 × 10 <6> (Pa) and tensile strength of 20 × 10 <6> (Pa). In addition, Young's modulus is
05-05-2019
9
also extremely high at 2.0 × 10 <6> (N / m <2>). As described above, since the giant
magnetostrictive member is formed of an element having high mechanical strength, it does not
burn out due to heat generation due to driving. Moreover, since the Young's modulus is high, it is
possible to secure the response to high frequency.
[0028]
The magnetic field generation unit 34 is a magnetic field generation coil which is disposed
around the giant magnetostrictive member 32 and generates a magnetic field oriented along the
displacement direction of the giant magnetostrictive member 32 according to the supply of a
drive current based on an audio signal. .
[0029]
The sound tube 35 is a so-called horn that is provided continuously with the sound output side of
the housing 31 and gradually expands in diameter forward (upward in the figure).
A sound path is formed by the arc-shaped inner wall surface of the acoustic tube 35.
[0030]
Thereby, in the second speaker 30 according to the present embodiment, when the drive current
based on the audio signal is supplied to the magnetic field generation unit (magnetic field
generation coil) 34, the magnetic field generation unit 34 is along the axial direction of the giant
magnetostrictive member 32. Generate a magnetic field of direction. In addition, the giant
magnetostrictive member 32 vibrates (extends and contracts) in the axial direction (the direction
of the arrow in the drawing) when the magnetic field is applied, and the dimension (length) is
displaced. Further, the air flow valve 36 is driven by the displacement of the giant
magnetostrictive member 32, and the air flow valve 36 adjusts the amount of air passing through
the air outlet 38, whereby a sound wave corresponding to the audio signal is output.
[0031]
As described above, the second speaker 30 according to the present embodiment is easy to
05-05-2019
10
assemble and operates the air flow valve 36 by displacing the magnetostrictive member 32 to
move the air flow passage of the compressed air toward the air outlet 38. By changing the size,
the flow rate of compressed air blown out from the air outlet 38 can be easily adjusted.
Therefore, in the present embodiment, the driven portion is a super magnetostrictive member
having high mechanical strength, and the driving portion can be a speaker in which the airflow
valve is not broken by the reaction by the pressure of the compressed air or the flowing air. In
addition, since the drive unit responds at high speed, the frequency response can be improved.
[0032]
It is a vertical side view showing a first embodiment of the first speaker according to the present
invention. It is a vertical side view which shows the 2nd Example of the 1st speaker which
concerns on this invention. It is a vertical side view showing the example of the 2nd speaker
concerning the present invention. It is a vertical side view showing a conventional horn type
speaker. It is a vertical side view showing a conventional air flow type speaker.
Explanation of sign
[0033]
10, 20 first speaker (horn type type speaker) 30 second speaker (air flow type type speaker) 11,
31 case 12, 32 super magnetostrictive member (super magnetostrictive element) 12a
displacement end portion 14, 34 magnetic field generating portion 15, 35 sound pipe (horn) 16
phase equalizer (equalizer) 18 radiator 36 air flow valve 36 a vibrating surface 37 air inlet 38 air
outlet
05-05-2019
11
Документ
Категория
Без категории
Просмотров
0
Размер файла
22 Кб
Теги
jp2008228248
1/--страниц
Пожаловаться на содержимое документа